Tissue burden of asbestos in nonoccupationally exposed individuals from east Texas

Our plain-English summary of Tissue burden of asbestos in nonoccupationally exposed individuals from east Texas, by R.F. Dodson, M.G. Williams, J. Huang, et al (American Journal of Industrial Medicine, 1999).

The study

• Authors: R.F. Dodson, M.G. Williams, J. Huang, J.R. Bruce
• Journal: American Journal of Industrial Medicine
• Published: 1999;35(3):281-6
• Cited by: 31 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: The potential for asbestos exposure among members of the general population is appreciable, considering its widespread use in many products. This study examined tissue burden of asbestos in such a population.

Methods: A group of 33 individuals who had no work history of occupational exposure to asbestos were included in the study. Tissue sections from areas adjacent to those sites sampled for digestion were found to be without ferruginous bodies (FB) or histopathology consistent with asbestos-induced changes. All individuals had 20 or less FBs per gram of digested wet lung, a number considered to reflect general population levels. Tissue analysis of uncoated fiber burden was carried out by analytical electron microscopy. There was a trend of a higher likelihood of FB and asbestos fiber content correlated with age.

Results: The data are not consistent with the findings that chrysotile is readily found in lung tissue from the general population, in that none was found in 19 of the cases. It was almost as likely that one would find anthophyllite (12 of 33 cases) in this study. The commercial amphiboles (amosite and crocidolite) were occasionally found in the tissue from the general population and, when observed, were few in numbers. Twenty-six of the patients had no FBs and ten had no uncoated asbestos fibers within the limits of detectability in this study.

Conclusions: The total tissue burden of asbestos in this study is much less than earlier reported observations from other general populations.

In plain English

This study examined autopsy lung tissue from 33 East Texans with no work history of occupational asbestos exposure. To be included, tissue sections had to show no ferruginous (asbestos) bodies or changes suggesting asbestos disease. Their digested lung also had to contain 20 or fewer ferruginous bodies per gram of wet lung. Uncoated fibers were counted by analytical electron microscopy. No ferruginous bodies were found in 26 people, and the other seven had 20 per gram of wet lung. No asbestos fibers were detected in 10 of the 33. Chrysotile was found in 14 people, anthophyllite in 12, tremolite in eight and actinolite in four. Amosite and crocidolite were each found in three people. The average uncoated asbestos concentration was 84,000 fibers per gram of dry lung across all 33, and 120,000 among the 23 with fibers. The highest, 290,000 fibers per gram of dry lung, was found in two people. Uncoated asbestos levels were positively correlated with age. The authors concluded that total asbestos burden was much less than earlier reports from other general populations. They noted that chrysotile clears from the lung more readily than amphibole.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Autopsy lung tissue study (light and analytical transmission electron microscopy of digested lung) in a general-population group
• Who was studied: 33 individuals from eastern Texas (rural areas or communities, no city of 250,000 or more) with no work history of occupational asbestos exposure; no ferruginous bodies or asbestos-type changes in tissue sections and 20 or fewer ferruginous bodies per gram wet lung in digests
• Exposure: Nonoccupational (general-population) exposure; the authors note asbestos in local industry and in schools, public buildings and homes. Fiber types measured: chrysotile, amosite, crocidolite, tremolite, actinolite, anthophyllite
• Main results:
  • Ferruginous bodies: none in 26 individuals; 7 individuals had 20 per gram wet weight
  • No asbestos fibers were detected in 10 of the 33 patients (mean detection limits 8,800 fibers per gram wet and 44,000 per gram dry)
  • Chrysotile was found in 14 of 33 cases; none was found in 19 cases
  • Anthophyllite was found in 12 of 33 cases
  • Tremolite was found in 8 cases and actinolite in 4; amosite and crocidolite were each found in 3 cases
  • Average uncoated asbestos concentration was 84,000 fibers per gram dry lung for all 33 samples and 120,000 per gram dry for the 23 patients with fibers
  • Highest uncoated asbestos concentration, 290,000 fibers per gram dry, in a 68-year-old woman (Case 31) and a 38-year-old man (Case 22)
  • Positive correlation between age and total uncoated asbestos concentrations (p less than 0.01), and a significant positive correlation between ferruginous bodies and uncoated asbestos
  • 79% of the asbestos fibers, considered as a group, were shorter than 5 micrometers
• The authors' conclusion: The authors concluded that the total tissue burden of asbestos in this group was much less than earlier reported observations from other general populations, with few ferruginous bodies found
• Limitations the authors state:
  • Chrysotile clears from the lung more readily than amphibole, so the measured burden represents a small fraction of inhaled chrysotile
  • The source of the tremolite could not be defined
  • Work histories may not capture all exposures

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile.

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Work History, Occupational Exposure, Ferruginous Bodies, Histopathology, Fiber Burden, Chrysotile, Anthophyllite.

Related studies

• Asbestos content in the lymph nodes of nonoccupationally exposed individuals — R.F. Dodson, J. Huang, et al. (2000)
• Asbestos content of omentum and mesentery in nonoccupationally exposed individuals — R.F. Dodson, M.F. O'Sullivan, et al. (2001)
• Assessment of asbestos burden in the placenta and tissue digests of stillborn infants in South Texas — A.K. Haque, D.M. Vrazel, et al. (1998)
• A clinical assessment and lung tissue burden from an individual who worked as a Libby vermiculite miner — B. Black, R.F. Dodson, et al. (2017)
• Asbestos burden in cases of mesothelioma from individuals from various regions of the United States — R.F. Dodson, R. Graef, et al. (2005)
• A clinical evaluation and tissue fiber burden analysis of a lifetime resident of Libby, Montana with adenocarcinoma of the lung — R.F. Dodson, B. Black, et al. (2020)

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